For what it's worth, Jude, I have dreams with all kinds of people in them, known and unknown, all the time, and I almost always remember them vividly because I'm a very light sleeper so I tend to wake up right after them when they're fresh in my mind. I've actually dreamed that I've died a couple of times - once by falling off a ledge, and once by plane crash. My husband was in both dreams and died with me in both. In both cases, we walked away from our bodies/the airplane lying there, and I said to him, "Are we dead?" and then woke up. I've always thought these were anxiety dreams about worrying that our marriage was dying. But one friend thinks they're past-lives dreams. I dunno. I have to say that like everything else, I can't believe in it without some kind of proof. Just not a very faithful person in that sense. And I haven't seen real proof yet. Then again, I haven't seen real proof to the contrary, either, so I'll withhold final judgment.
As far as the dreams I have with dozens of people in them who I don't believe I know, my thinking on this is that these are all the people I see every day on the periphery - my subconscious registers them, but not my conscious mind. So at night, my subconscious does a "core dump" to clear out those memory cells and releases all those people into my dreams.
If I did believe 100% in past lives, I'd believe that my mother and I have been soulmates (platonically, of course) through the ages. And that I've been a gay man at least once. I just understand (or think I do, at least) way too much intuitively about what it is to be a man, and what it is to be a man who loves other men, than a woman by all rights should. I always have - since *way* before Brokeback (but it's probably one of the reasons why these characters break my heart so much). I would also believe that I've lived in England - maybe even many times over. I've been an Anglophile for as long as I can remember, but I didn't see England for the first time until I was 30. I've since been back there twice because each time I go, I believe I am home. I've only felt a natural pull to a place one other time in my life, and that was when I went to Rhode Island for a wedding once about 15 years ago. I felt that pull while driving through a small town between Providence and the little seaside town in which our friends got married and could find no logical reason for it, since it was nothing, really, like anywhere I'd lived or been before.